1. Field of the Invention
The invention relates in general to a display module and a display device, and more particularly to a two dimensional and three dimensional switchable display module and display device.
2. Description of the Related Art
For the past few years, technologies and peripheral products for three dimensional display are developed rapidly. Three dimensional stereoscopic display provides different images to binocular vision by utilizing a parallax between human eyes. The different images are received by individual eyes, merged by the brain and be developed into a stereoscopic image.
Most of the three dimensional displays should work with a three dimensional glasses. The three dimensional glasses are costly and inconvenient to users. Naked eye three dimensional (naked eye 3D) technology is then produced to solve the problem. The main types of naked eye 3D display are lenticular lens type and parallax barrier type.
The lenticular lens type display use lens to separate light propagation path. The separated light emits to the left eye and the right eye separately and induces human brain to generate stereoscopic visual effect. The parallax barrier type display use a barrier as a light shelter. The shelter area and a light transmissible area are interlaced each other, such that the images observed by the user comprises a separated left eye image and a separated right eye image and can be merged by human brain.
FIG. 1 illustrates a schematic diagram of a conventional three dimensional display 100. A barrier 15 is disposed in front of a display panel 11. The light emitting from a backlight module 13 passes through a light shelter area and a light transmissible area such that light of visible pixels are respectively transported to the left and right eyes. When the display panel displays different images in odds pixels and even pixels and light of odd pixels and even pixels are transported to the left eye and the right eye respectively, the left eye and the right eye see different images. Therefore, a three dimensional image can be construct by human brain.
However, neither lenticular lens type display nor parallax barrier type display requires specific alignment with display panel 11 to perform the three dimensional effect. Thus, the lenticular lens or parallax barrier need to be fixed on the display panel 11 after an accurate alignment procedure. The manufacturing cost of the three dimensional display increases due to the specific alignment procedure. Besides, since the lenticular lens or parallax barrier is fixed to the display panel 11, the transmittance of the display is reduced seriously in two dimension mode and the user can not switch the three dimensional display effect into two dimensional display effect discretionary.